This application is a continuation-in-part of application Ser. No. 809,654 filed Mar. 24, 1969. This invention relates generally to the field of high-speed electronic circuits wherein a "majority carrier diode" is employed as a circuit component thereof, and the high-speed operational characteristic of the circuits is thereby substantially improved.
Heretofore, the Schottky barrier diode was known and constituted one version of the "majority carrier diode," wherein a metal semiconductor junction is used instead of the conventional PN or NP junction, and the current is carried by the majority carriers instead of the minority carriers as was the case in the conventional junction.
It has been previously proposed that in an integrated circuit including a transistor, the saturation period of the transistor is shortened or the saturation phenomena thereof is utterly eliminated by connecting the "majority carrier diode" between some of the electrodes of the transistor or between an electrode thereof and the ground potential.
We made a Schottky barrier diode of a size comparable to the transistor (approximately 10 microns square) utilizing molybdenum, and found that when the diode current is 3 mA, the voltage drop across the diode was about 0.35 V. This voltage drop was almost constant (actually increased about 26 mV) even when the diode current was doubled.
On the other hand, in a high-speed integrated circuit of faster than 10 ns, a high quality transistor having a width of the emitter of 10 microns, length of the emitter of several tens of microns square is used for the output transistor, and, in this case, the collector series resistance is about 20 ohms.
It should be noted that in the ordinary integrated circuit of standard nature, the saturation of the transistor becomes significant when the real base voltage, excluding the effect of the parasitic resistances, exceeds approximately 0.5 V (this value is somewhat different depending on the manufacture).
As illustrated in FIG. 1 of the accompanying drawings, which will be described hereinafter, when the Schottky barrier diode is connected into an integrated circuit comprising: a transistor Q, a parasitic resistor .gamma.c, an input terminal t.sub.in, and an output terminal t.sub.o, and when an input current I.sub.in = 3mA and a load current I.sub.L = 10mA are caused to flow through the circuit, a voltage drop of 0.26 V or more is created across the series resistor .gamma.c. As a result, the voltage across the base collector junction becomes more than 0.61 V at the "ON" condition of the transistor, and the transistor Q shows a severe saturation.
The reason for this is in the fact that the load current flows through the same path as the diode current, and if the paths for these two currents are substantially separated, the operation of the Schottky barrier diode (hereinafter abbreviated as SBD) is effectuated and far larger current can be passed through the load.